Later that night at Eleven the Doctor took a flashlight and went down to the common room entrance.

"Password?" The Fat Lady asked.

The Doctor looked the portrait up and down"Not going in." He said said as the portrait swung open and the golden trio left.

He turned on the flashlight and helped Nevill into the common room before the three left. Harry, Ron, and Hermione turned to look at him.

"Professor these two, are trying to sneak to the trophy room." Hermione said.

"I know." The Doctor said.

"Their out of bed past hours." Hermione replied.

"I know." The Doctor observed.

"You should do something." She said a little exasperated.

The Doctor looked at her. "Hermione you're absolutely right," He turned to the two boys. "Harry, Ron. Let's go to the trophy room." He said brightly.

Hermione looked absolutely horrified by this.

He turned off his Flashlight. "Now then you three. The fat lady just left for a spot of wine in one of the other portraits and Mrs. Norris will be here in about." The Doctor checked his watch.

"Three minutes. Which means we should get going chop chop." He said.

The Four of them began to descend the staircase towards the trophy room.

"I don't get it. How did you know we were planning to go to the trophy room? We never said anything to you." Ron asked.

"That is a very good question Mr. Weasley. And the answer is… a secret." The Doctor replied.

"No Ron actually makes a very good point " Harry pondered. "You've seemingly been ahead from the moment I met you. The only time I saw you surprised was when I almost got expelled."

The Doctor looked at Harry. "You're cleverer than you look Mr. Potter." He sighed. "Fine fine. Maybe when you're all a bit older, I'll tell you what's going on." He said.

"Now then let's go." He followed them all down the stairs still having a gleeful childish look on his face. No matter how many times he walked through these corridors it never got old.

"Sir. Shouldn't you be stopping them?" Hermione asked wondering why a teacher was letting this happen.

The Doctor kneeled to get eye level with the eleven year old girl. "Hermione, rules are… well rules are important things. But sometimes there are more important things. There are very few rules I haven't broken in my lifetimes." The Doctor said gently almost sadly. He smiled and wiped some dust off her pajamas. "But yes, there are some rules we should strive to never break."

Without another word he kept walking. Hermione had picked up on one word. "Lifetimes?" She said to herself.

The Doctor smiled hearing that. He'd be impressed with anyone clever enough to figure out who he was from such a simple hint. Then she asked a question he did not expect.

"Did you ever break any of those rules. The ones you should never break?" She asked.

The Doctor stopped again. He looked at the floor. "I have… a few times… and I've been worse for it." He said honestly.

"What did you do?" She asked.

"A very bad thing. Something that I'll regret for the rest of my life." He said. "Never you mind. It was Eons ago."

As they approached the trophy room The Doctor stepped them. He inched his head and looked past the wall. Filch was there. Already? That was too fast.

"Go, run." The Doctor whispered.

"But what about Malfoy?" Ron asked loudly.

The Doctor shushed him. He looked at saw Filch start to limp over. "You've been had. Run, get out of here, go." He hissed.

He walked into the trophy room almost bumping into Filch. "Hello Mr. Filch." He said.

"Doctor, you're out very late." Filch said.

The Doctor lifted his sleeve raised his arm up looking at watch. "So I am. Bad Habit. Can't sleep." He said.

"And what of those students with you. Were they also unable to sleep?" Filch asked accusingly.

"Argus I am HURT that you would think I would just disregard the rules like that." The Doctor said dramatically.

"Why are you hiding them. Don't want to get in trouble?" He asked.

"Get who in trouble? I've absolutely no idea what you mean. Now then I must be off now. I need to check some papers for my class tomorrow." The Doctor excused himself and left the Great Hall and headed for the third floor corridor.

He heard banging on the door. "You three alright in there?" He asked.

"Doctor!" Harry yelled. "Help! We can't the door back open." The Doctor confused, pulled the sonic Screwdriver from his pocket and opened the door.

"Okay okay, it's just a...dog." The Doctor looked on at where Fluffy should have been.

"You three get to the common room. Now." He commanded. They did as they were told.

The Doctor stepped into the room looking at the creature that stood in Fluffy's space.

"You. How did you get here? What are you doing here? Why are you here?" He asked. "ANSWER ME! You aren't supposed to be here so why are you! Who brought you!?"

"I AM HERE TO EXTERMINATE INTRUDERS! MY ORDERS ARE TO PROTECT THE STONE. PROTECT! PROTECT! PROTECT!" The Dalek said.

"You know who I am. Now don't lie to me why are you here?" He asked.

"YES. YOU ARE THE PREDATOR OF THE DALEKS. THE DOCTOR! I DO NOT LIE! I AM HERE TO PROTECT THE STONE!" The Dalek said.

The Doctor stood eyeing the Dalek. "Okay so say I believe you, what you are you protecting it for? What do the Daleks get out of this arrangement because you aren't here to help humanity. Your here help some Dalek cause."

"YOU WILL DISCONTINUE THIS LINE OF QUESTIONING! DISCONTINUE! DISCONTINUE!" The Dalek ordered.

"No I won't not until I have an answer." The Doctor said calmly yet enraged to see his oldest enemy here. "Why are you protecting the stone."

"I WAS ORDERED TO PROTECT THE STONE!" It answered.

"By who?" The Doctor asked.

"ALBUS DUMBLEDORE!"

The Doctor just stood there. "And what does the Dalek race get out of helping the Headmaster of a magic school."

The Dalek was silent. It slowly clicked for the Doctor. "Oh… oh I see. You don't do you. Something is keeping you here. Well then. I'm going to talk to the head master."

The Doctor left and headed for Dumbledore's office. When he got there he realized he didn't know the password.

"Let's see… using everything I know about Dumbledore… Lemon Drop." The Doctor said.

The eagle statue didn't move.

"Sherbert lemon? Chocolate Frog?" Neither worked.

"Oh I dunno. Fizzing Wizzby." The Doctor guessed randomly.

At those words the eagle began to rotate and a staircase appeared. The Doctor chuckled. "Really now? Okay."

He walked up the stairs to the Headmaster's office. He opened the door without bothering to knock. He walked up to Fawks and pet the bird's head stroking his feathers. He looked around the room seeing portraits of the previous headmasters of Hogwarts. He walked up to Dumbledore's desk seeing it empty.

He looked over at where the pensive would be. Best not to look. The Doctor turned away from it trying to think of something else. But his eyes kept going back. His curiosity was peaking. How could he not take a look. He walked over to the locked cabinet. Locks were no match for him.

He pulled out the Sonic Screwdriver and pressed it against the lock. It buzzed momentarily before the lock clicked and the Doctor opened the cabinet.

The Doctor looked into the Pensive. There was a memory already there. The fight between Dumbledore and Grindelwald. The Doctor felt himself get sucked into the memory. There a feeling as though he was passing through a veil of sorts. Then he stood on a street. Not particularly important street just any old street.

"Hello." He heard someone see. He looked to see himself. Not just himself but his previous incarnation.

The Doctor looked around and pointed at himself. The Tenth Doctor nodded. "Yeah you." He said.

"This is several kinds of impossible. How are you seeing me? How are you… you?" He asked.

The Tenth Doctor opened his mouth thinking through the next words. "Well… I can't see you. Technically I'm speaking to thin air. But I remember being you and having this conversation. Mind you for me it's very one sided."

The Doctor looked at him. "But I can't be you. I've already been you. How are you… you?" He asked again.

"Long story. You'll find out soon." The Tenth Doctor said.

"And why are you even here?" The Doctor asked.

"Well. That's a longer story. And I really haven't the time to explain it. After this I'm going to the TARDIS and going home. Back to my Universe. Just saying some final goodbyes." The other Doctor replied.

"Wait a minute? You're me? You're my future?" The Doctor asked.

The Tenth Doctor nodded. "Yeah. I know it's all very strange. Don't worry. It all works out for the best in the end." He said. "Don't worry. The Universe will sort it out. I'm pretty sure that as soon as I head back to our Universe I'll turn back into you."

"And you're choosing to go back? Last time I was you I hated the idea of changing." The Doctor said.

"I've come to terms with it." The Tenth Doctor replied. "Anyway busy years ahead. Go and talk to Albus. Ask him your questions and… be prepared. The Dalek is only one of many changes you'll have to face." The Tenth Doctor said.

The Doctor felt himself get pulled out of the Pensive and stumbled back.

"Hello doctor." A calm voice said.

The Doctor spun around and looked at Albus. "Professor." He said.

Dumbledore walked to the pensive. "You know during that fight I had always noticed you talking to thin air. I could never figure out why? I think I finally understand. Even now your views and sense of time still amaze me." He said.

"Yes… sometimes I amaze myself… nevermind. You have a Dalek protecting the stone? How'd you manage that?" He asked.

"Oh that?" Albus chuckled. "That Dalek has been imprisoned in the school for many years. It was chained up and magically bound in the forbidden forest. It's Bewitched. Can't kill students or staff unless they get too close. Even then I've left a trick to getting past it in times of need." He explained.

"When Nicholas asked that I protect the stone I thought it a jolly idea to put that other worlder to work."

The Doctor stared. "How long has it been a prisoner here?"

"Over 34 years." Albus said. "What if it escapes?" The Doctor asked.

"It can only escape in the event of my death." Albus said. "It's quite safe I assure you."

"No. No it's not. Dalek's can't be reasoned with? They can't be controlled." The Doctor stepped forward.

He looked at Albus and spoke quietly. "If that thing breaks free, and it will break free, it will kill every single person in the school."

"I thank you for your opinion Doctor. But as of right now I know things you don't. For example, it was not my idea to keep the Dalek here, it was yours. If you will not trust my judgment that trust your own." Dumbledore said calmly.

The Doctor had no rebuttal. Dumbledore smiled a friendly smile.

"Now do be sure to take some droobles before you leave old friend." The Headmaster said putting some of the gum in the Doctor's hand.

The Doctor nodded. "Right then. If you insist… I'll trust you." He turned and made for the door.